Fuse-plug



FUSE PLUG. APPLICATIONTILED JU LY\7,1919.

1,373,696 Patented Apr. 5,1921.

W/ T/VESSES v IN l/E IV TOR .& .44; JIM 04F v I; By W ATTORNEYS UNITED STATES PATENT OFFICE.

' JOHN WILLIAM WULF, OI SAN JUAN, PORTO RICO.

FUSE-PLUG.

To all whom it may concern: Be it known that I, JOHN WILLIAM WULF, a citizen of the United States, and a resident of San Juan, Porto Rico, have invented a new and .useful Improved Fuse-Plug, of which the following is a full, clear, and exact description;

This invention'relatesto anew and improved fuse plug, and has reference more particularly to a device of this kind, which comprises a body having spaced terminals and a fuse connecting the terminals, the body providing a receptacle fora spare fuse, whichis normally separated from the live fuse connecting, the terminals.

An object of the invention is to provide a simple and durable fuse plug for use with 7 electric circuits of different kinds, which can the live fuse.

'be inexpensively produced, and in which the fuse is readily renewable.-

A further object of the invention is to provide a fuse plug in which soldered connections are avoided, in which a substantial length of spare fuse is available at all times,

for replacing thelive fuse should the same be burned out, and in which the spare fuse is protected against injury which might be occasioned incident to the burning out of A still further object of the invention is to provide afuse plug in which the fuse is easily visible at all times; which has a selfcontained spare fuse for replacing the burned out fuse, and which providesmeans for guarding the spare fuse against injury, while leaving the same readily available for use.

The invention consists in the construction and combination of parts, to be more fully described hereinafter and particularly set forth in the claims.

Reference is to be had to the accompanying drawings forming a part of this specification. in which similar characters of reference indicate corresponding parts in all the views, and in which- Figure 1 is a longitudinal section of an embodiment of my invention;

Fig. 2 is a plan view showing the covering cap in cross section;

' Fig. 3 is a partial longitudinal section at right angles to the section of Fig. 1; and

Fig. 1 is a detail view of a'terminal employed with the device.

Before proceeding to a more detailed ex- Specification of Letters Patent.

. shapes.

;a socket adapted to receive it.

per end, the plug has a laterally extended Patented Apr. 5, 1921.

Application filed July 7, 1919. Serial No. 308,983.

connection with electric circuits of different" kinds. It may be fashioned from any suitable material customarily employed, and may be roduced in different sizes and Certain of the details of construction form no part of the invention and may be varied in accordance with necessity or preference, without departing from the splrlt of the invention.

Referring more particularly to the draw- I ings, I provide a fuse body 10, of porcelain or other di-electric material, and having the lower part 11 threaded to receive a suitable,

correspondingly threaded metal ferrule 12,

by means of which the plug is screwed into At the uphead 13, whichis threaded to receive a correspondingly threaded flange 14 of an annular cap 15 of sheet metal or the like. The annular cap seats upon the top of the fuse and holds in position a glass or mica sheet 16 extending over the open-ended chamber 17 formed within the'body, so that the interior of the plug can be inspected through the transparent sheet 16.

The lower end 18 of the body is prefer ably tapered. It has a longitudinal bore 19 opening into the chamber 17. A cylindrical terminal 20 is received in the bore 19 and has a flat head 21 seating against the lower end of the body and adapted to engage a suitable contact of the electric circuit with which the fuse plug is used. The terminal 20 is provided with asubstantially central, threaded bore 20, and has two tapered, spaced fingers 20 at the end opposite the head 21. A binding or cap screw 26 is received in the bore 20. and. serves to secure the wire 28 to the terminal. The bottom of the chamber 17 isprovided with a pair of opposite grooves 19 adapted to receive the fingers 20 when the latter are spread apart and turned outwardly as the screw 26 is forced home. In this way the terminal 20 is prevented from turning when the fuse plug is screwed into the socket. At its upper end the chamber 17 has a lateral extension or recess 22 from which projects a metal plate 23. A downwardly extending opening 24 is formed in the bodyand extends from the recess to the outside of the body, just under the head 13. The plate 23 has an extension 25 disposed in the opening 24: and contacting with the metal ferrule12,

as is shown in Fig. 3. The terminal 20 and the plate terminal 23 are respectively provided with screws 26 and 27 by means of which a length of fusible wire 28, constituting the fuse proper, is securedto the'termlnals. eludes the terminal 20, the fuse wire 28, the terminal 23, and the ferrule 12.

An annular channel 29 is formed in the upperface of the body, surrounding the chamber 17 and preferably con'centric'there tend over and close the channel or' chamber 29, so that when the plug is in use the spare fuse is protected against injury should the fuse 28, blow out. It is readily made available for use, however, by simply unscrewing the cap.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A fuse plug, comprising a body, spaced terminals carried thereby, and a fuse connecting said terminals said body having a part adapted for the reception of a spare fuse. normally separated from said fuse connecting said terminals, said spare fuse being connected to one of said terminals and branching therefrom for disposition in said receiving part. v

2. A fuse plug, comprising a body having spaced terminals, and a fuse connecting said terminals, said fuse having a spare length extending beyond one of said-terminals, said body having a chamber in its outer end adapted for the reception of said spare length.

3. A fuse plug, comprising a body having spaced terminals, and a fuse connecting said terminals, said fuse having a spare length c0nnected.to and extending beyond one of said terminals, said body having an annular groove in its outer face forming a chamber adapted for the reception of said spare It will be seen that the circuit inlength and having an opening near said one terminal. v

4. A fuse plug, comprising a body having spaced terminals, a fuse connecting said terminals, said fuse having a spare length extending beyond one of said terminals, said body having an annular chamber in its outer end adapted for the reception of said spare length and having an opening near said one terminal, and means for normally covering said chamber to protect said spare length of fuse therein.

5. A fuse plug, comprising a hollow body, terminals extending into said hollow body, a coverfor said hollow body, and a fuse connecting said terminals, said body having an I annular chamber in one end adapted for the reception of a spare fuse, and normally covered and closed by said cover.

6. A fuse plug, comprising a body having a threaded part and a chamber therein op'en ing at one end of said body, terminals extending into said chamber and adapted to be connected by a fuse, a transparent plate over the open end of said chamber, acap removably fitted upon said body and holding said plate in position, said body having a second chamber surrounding said first chamber and opening near one of said terminals, said second chamber being adapted for the reception of spare fuse and being normally covered by said cap. I

7. A fuse plug, comprising a body having a chamber opening at one end of said body, said bodyha'ving at the upper end thereof a. second chamber surrounding said first chamber, said first cha ber having a lateral recess extending to said second chamber, a terminal arranged in said recess and extending into the said firstchamber, a second terminal at the opposite end of said body and extending into. said chamber being adapted for the reception of a spare fuse, and a cover over the open end first chamber, a ferrule encompassing said body, an electrical COIlIlECtlOIl. between 'sald first terminal and said ferrule, said second of said body and closing both of said chambers.

JOHN WILLIAM WULF. 

